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<FONT color="green">001</FONT>    /*<a name="line.1"></a>
<FONT color="green">002</FONT>     * Licensed to the Apache Software Foundation (ASF) under one or more<a name="line.2"></a>
<FONT color="green">003</FONT>     * contributor license agreements.  See the NOTICE file distributed with<a name="line.3"></a>
<FONT color="green">004</FONT>     * this work for additional information regarding copyright ownership.<a name="line.4"></a>
<FONT color="green">005</FONT>     * The ASF licenses this file to You under the Apache License, Version 2.0<a name="line.5"></a>
<FONT color="green">006</FONT>     * (the "License"); you may not use this file except in compliance with<a name="line.6"></a>
<FONT color="green">007</FONT>     * the License.  You may obtain a copy of the License at<a name="line.7"></a>
<FONT color="green">008</FONT>     *<a name="line.8"></a>
<FONT color="green">009</FONT>     *      http://www.apache.org/licenses/LICENSE-2.0<a name="line.9"></a>
<FONT color="green">010</FONT>     *<a name="line.10"></a>
<FONT color="green">011</FONT>     * Unless required by applicable law or agreed to in writing, software<a name="line.11"></a>
<FONT color="green">012</FONT>     * distributed under the License is distributed on an "AS IS" BASIS,<a name="line.12"></a>
<FONT color="green">013</FONT>     * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.<a name="line.13"></a>
<FONT color="green">014</FONT>     * See the License for the specific language governing permissions and<a name="line.14"></a>
<FONT color="green">015</FONT>     * limitations under the License.<a name="line.15"></a>
<FONT color="green">016</FONT>     */<a name="line.16"></a>
<FONT color="green">017</FONT>    package org.apache.commons.net.util;<a name="line.17"></a>
<FONT color="green">018</FONT>    <a name="line.18"></a>
<FONT color="green">019</FONT>    import java.util.regex.Matcher;<a name="line.19"></a>
<FONT color="green">020</FONT>    import java.util.regex.Pattern;<a name="line.20"></a>
<FONT color="green">021</FONT>    <a name="line.21"></a>
<FONT color="green">022</FONT>    /**<a name="line.22"></a>
<FONT color="green">023</FONT>     * A class that performs some subnet calculations given a network address and a subnet mask.<a name="line.23"></a>
<FONT color="green">024</FONT>     * @see "http://www.faqs.org/rfcs/rfc1519.html"<a name="line.24"></a>
<FONT color="green">025</FONT>     * @author &lt;rwinston@apache.org&gt;<a name="line.25"></a>
<FONT color="green">026</FONT>     * @since 2.0<a name="line.26"></a>
<FONT color="green">027</FONT>     */<a name="line.27"></a>
<FONT color="green">028</FONT>    public class SubnetUtils {<a name="line.28"></a>
<FONT color="green">029</FONT>    <a name="line.29"></a>
<FONT color="green">030</FONT>        private static final String IP_ADDRESS = "(\\d{1,3})\\.(\\d{1,3})\\.(\\d{1,3})\\.(\\d{1,3})";<a name="line.30"></a>
<FONT color="green">031</FONT>        private static final String SLASH_FORMAT = IP_ADDRESS + "/(\\d{1,3})";<a name="line.31"></a>
<FONT color="green">032</FONT>        private static final Pattern addressPattern = Pattern.compile(IP_ADDRESS);<a name="line.32"></a>
<FONT color="green">033</FONT>        private static final Pattern cidrPattern = Pattern.compile(SLASH_FORMAT);<a name="line.33"></a>
<FONT color="green">034</FONT>        private static final int NBITS = 32;<a name="line.34"></a>
<FONT color="green">035</FONT>    <a name="line.35"></a>
<FONT color="green">036</FONT>        private int netmask = 0;<a name="line.36"></a>
<FONT color="green">037</FONT>        private int address = 0;<a name="line.37"></a>
<FONT color="green">038</FONT>        private int network = 0;<a name="line.38"></a>
<FONT color="green">039</FONT>        private int broadcast = 0;<a name="line.39"></a>
<FONT color="green">040</FONT>    <a name="line.40"></a>
<FONT color="green">041</FONT>        /** Whether the broadcast/network address are included in host count */<a name="line.41"></a>
<FONT color="green">042</FONT>        private boolean inclusiveHostCount = false;<a name="line.42"></a>
<FONT color="green">043</FONT>    <a name="line.43"></a>
<FONT color="green">044</FONT>    <a name="line.44"></a>
<FONT color="green">045</FONT>        /**<a name="line.45"></a>
<FONT color="green">046</FONT>         * Constructor that takes a CIDR-notation string, e.g. "192.168.0.1/16"<a name="line.46"></a>
<FONT color="green">047</FONT>         * @param cidrNotation A CIDR-notation string, e.g. "192.168.0.1/16"<a name="line.47"></a>
<FONT color="green">048</FONT>         * @throws IllegalArgumentException if the parameter is invalid,<a name="line.48"></a>
<FONT color="green">049</FONT>         * i.e. does not match n.n.n.n/m where n=1-3 decimal digits, m = 1-3 decimal digits in range 1-32<a name="line.49"></a>
<FONT color="green">050</FONT>         */<a name="line.50"></a>
<FONT color="green">051</FONT>        public SubnetUtils(String cidrNotation) {<a name="line.51"></a>
<FONT color="green">052</FONT>            calculate(cidrNotation);<a name="line.52"></a>
<FONT color="green">053</FONT>        }<a name="line.53"></a>
<FONT color="green">054</FONT>    <a name="line.54"></a>
<FONT color="green">055</FONT>        /**<a name="line.55"></a>
<FONT color="green">056</FONT>         * Constructor that takes a dotted decimal address and a dotted decimal mask.<a name="line.56"></a>
<FONT color="green">057</FONT>         * @param address An IP address, e.g. "192.168.0.1"<a name="line.57"></a>
<FONT color="green">058</FONT>         * @param mask A dotted decimal netmask e.g. "255.255.0.0"<a name="line.58"></a>
<FONT color="green">059</FONT>         * @throws IllegalArgumentException if the address or mask is invalid,<a name="line.59"></a>
<FONT color="green">060</FONT>         * i.e. does not match n.n.n.n where n=1-3 decimal digits and the mask is not all zeros<a name="line.60"></a>
<FONT color="green">061</FONT>         */<a name="line.61"></a>
<FONT color="green">062</FONT>        public SubnetUtils(String address, String mask) {<a name="line.62"></a>
<FONT color="green">063</FONT>            calculate(toCidrNotation(address, mask));<a name="line.63"></a>
<FONT color="green">064</FONT>        }<a name="line.64"></a>
<FONT color="green">065</FONT>    <a name="line.65"></a>
<FONT color="green">066</FONT>    <a name="line.66"></a>
<FONT color="green">067</FONT>        /**<a name="line.67"></a>
<FONT color="green">068</FONT>         * Returns &lt;code&gt;true&lt;/code&gt; if the return value of {@link SubnetInfo#getAddressCount()}<a name="line.68"></a>
<FONT color="green">069</FONT>         * includes the network address and broadcast addresses.<a name="line.69"></a>
<FONT color="green">070</FONT>         * @since 2.2<a name="line.70"></a>
<FONT color="green">071</FONT>         */<a name="line.71"></a>
<FONT color="green">072</FONT>        public boolean isInclusiveHostCount() {<a name="line.72"></a>
<FONT color="green">073</FONT>            return inclusiveHostCount;<a name="line.73"></a>
<FONT color="green">074</FONT>        }<a name="line.74"></a>
<FONT color="green">075</FONT>    <a name="line.75"></a>
<FONT color="green">076</FONT>        /**<a name="line.76"></a>
<FONT color="green">077</FONT>         * Set to &lt;code&gt;true&lt;/code&gt; if you want the return value of {@link SubnetInfo#getAddressCount()}<a name="line.77"></a>
<FONT color="green">078</FONT>         * to include the network and broadcast addresses.<a name="line.78"></a>
<FONT color="green">079</FONT>         * @param inclusiveHostCount<a name="line.79"></a>
<FONT color="green">080</FONT>         * @since 2.2<a name="line.80"></a>
<FONT color="green">081</FONT>         */<a name="line.81"></a>
<FONT color="green">082</FONT>        public void setInclusiveHostCount(boolean inclusiveHostCount) {<a name="line.82"></a>
<FONT color="green">083</FONT>            this.inclusiveHostCount = inclusiveHostCount;<a name="line.83"></a>
<FONT color="green">084</FONT>        }<a name="line.84"></a>
<FONT color="green">085</FONT>    <a name="line.85"></a>
<FONT color="green">086</FONT>    <a name="line.86"></a>
<FONT color="green">087</FONT>    <a name="line.87"></a>
<FONT color="green">088</FONT>        /**<a name="line.88"></a>
<FONT color="green">089</FONT>         * Convenience container for subnet summary information.<a name="line.89"></a>
<FONT color="green">090</FONT>         *<a name="line.90"></a>
<FONT color="green">091</FONT>         */<a name="line.91"></a>
<FONT color="green">092</FONT>        public final class SubnetInfo {<a name="line.92"></a>
<FONT color="green">093</FONT>            private SubnetInfo() {}<a name="line.93"></a>
<FONT color="green">094</FONT>    <a name="line.94"></a>
<FONT color="green">095</FONT>            private int netmask()       { return netmask; }<a name="line.95"></a>
<FONT color="green">096</FONT>            private int network()       { return network; }<a name="line.96"></a>
<FONT color="green">097</FONT>            private int address()       { return address; }<a name="line.97"></a>
<FONT color="green">098</FONT>            private int broadcast()     { return broadcast; }<a name="line.98"></a>
<FONT color="green">099</FONT>    <a name="line.99"></a>
<FONT color="green">100</FONT>            private int low() {<a name="line.100"></a>
<FONT color="green">101</FONT>                return (isInclusiveHostCount() ? network() :<a name="line.101"></a>
<FONT color="green">102</FONT>                    broadcast() - network() &gt; 1 ? network() + 1 : 0); <a name="line.102"></a>
<FONT color="green">103</FONT>            }<a name="line.103"></a>
<FONT color="green">104</FONT>            <a name="line.104"></a>
<FONT color="green">105</FONT>            private int high() { <a name="line.105"></a>
<FONT color="green">106</FONT>                return (isInclusiveHostCount() ? broadcast() :<a name="line.106"></a>
<FONT color="green">107</FONT>                    broadcast() - network() &gt; 1 ? broadcast() -1  : 0); <a name="line.107"></a>
<FONT color="green">108</FONT>            }<a name="line.108"></a>
<FONT color="green">109</FONT>    <a name="line.109"></a>
<FONT color="green">110</FONT>            /**<a name="line.110"></a>
<FONT color="green">111</FONT>             * Returns true if the parameter &lt;code&gt;address&lt;/code&gt; is in the<a name="line.111"></a>
<FONT color="green">112</FONT>             * range of usable endpoint addresses for this subnet. This excludes the<a name="line.112"></a>
<FONT color="green">113</FONT>             * network and broadcast adresses.<a name="line.113"></a>
<FONT color="green">114</FONT>             * @param address A dot-delimited IPv4 address, e.g. "192.168.0.1"<a name="line.114"></a>
<FONT color="green">115</FONT>             * @return True if in range, false otherwise<a name="line.115"></a>
<FONT color="green">116</FONT>             */<a name="line.116"></a>
<FONT color="green">117</FONT>            public boolean isInRange(String address) {<a name="line.117"></a>
<FONT color="green">118</FONT>                return isInRange(toInteger(address));<a name="line.118"></a>
<FONT color="green">119</FONT>            }<a name="line.119"></a>
<FONT color="green">120</FONT>    <a name="line.120"></a>
<FONT color="green">121</FONT>            private boolean isInRange(int address) {<a name="line.121"></a>
<FONT color="green">122</FONT>                int diff = address - low();<a name="line.122"></a>
<FONT color="green">123</FONT>                return (diff &gt;= 0 &amp;&amp; (diff &lt;= (high() - low())));<a name="line.123"></a>
<FONT color="green">124</FONT>            }<a name="line.124"></a>
<FONT color="green">125</FONT>    <a name="line.125"></a>
<FONT color="green">126</FONT>            public String getBroadcastAddress() {<a name="line.126"></a>
<FONT color="green">127</FONT>                return format(toArray(broadcast()));<a name="line.127"></a>
<FONT color="green">128</FONT>            }<a name="line.128"></a>
<FONT color="green">129</FONT>    <a name="line.129"></a>
<FONT color="green">130</FONT>            public String getNetworkAddress() {<a name="line.130"></a>
<FONT color="green">131</FONT>                return format(toArray(network()));<a name="line.131"></a>
<FONT color="green">132</FONT>            }<a name="line.132"></a>
<FONT color="green">133</FONT>    <a name="line.133"></a>
<FONT color="green">134</FONT>            public String getNetmask() {<a name="line.134"></a>
<FONT color="green">135</FONT>                return format(toArray(netmask()));<a name="line.135"></a>
<FONT color="green">136</FONT>            }<a name="line.136"></a>
<FONT color="green">137</FONT>    <a name="line.137"></a>
<FONT color="green">138</FONT>            public String getAddress() {<a name="line.138"></a>
<FONT color="green">139</FONT>                return format(toArray(address()));<a name="line.139"></a>
<FONT color="green">140</FONT>            }<a name="line.140"></a>
<FONT color="green">141</FONT>    <a name="line.141"></a>
<FONT color="green">142</FONT>            /**<a name="line.142"></a>
<FONT color="green">143</FONT>             * Return the low address as a dotted IP address.<a name="line.143"></a>
<FONT color="green">144</FONT>             * Will be zero for CIDR/31 and CIDR/32 if the inclusive flag is false.<a name="line.144"></a>
<FONT color="green">145</FONT>             * <a name="line.145"></a>
<FONT color="green">146</FONT>             * @return the IP address in dotted format, may be "0.0.0.0" if there is no valid address<a name="line.146"></a>
<FONT color="green">147</FONT>             */<a name="line.147"></a>
<FONT color="green">148</FONT>            public String getLowAddress() {<a name="line.148"></a>
<FONT color="green">149</FONT>                return format(toArray(low()));<a name="line.149"></a>
<FONT color="green">150</FONT>            }<a name="line.150"></a>
<FONT color="green">151</FONT>    <a name="line.151"></a>
<FONT color="green">152</FONT>            /**<a name="line.152"></a>
<FONT color="green">153</FONT>             * Return the high address as a dotted IP address.<a name="line.153"></a>
<FONT color="green">154</FONT>             * Will be zero for CIDR/31 and CIDR/32 if the inclusive flag is false.<a name="line.154"></a>
<FONT color="green">155</FONT>             * <a name="line.155"></a>
<FONT color="green">156</FONT>             * @return the IP address in dotted format, may be "0.0.0.0" if there is no valid address<a name="line.156"></a>
<FONT color="green">157</FONT>             */<a name="line.157"></a>
<FONT color="green">158</FONT>            public String getHighAddress() {<a name="line.158"></a>
<FONT color="green">159</FONT>                return format(toArray(high()));<a name="line.159"></a>
<FONT color="green">160</FONT>            }<a name="line.160"></a>
<FONT color="green">161</FONT>            <a name="line.161"></a>
<FONT color="green">162</FONT>            /**<a name="line.162"></a>
<FONT color="green">163</FONT>             * Get the count of available addresses.<a name="line.163"></a>
<FONT color="green">164</FONT>             * Will be zero for CIDR/31 and CIDR/32 if the inclusive flag is false.<a name="line.164"></a>
<FONT color="green">165</FONT>             * @return the count of addresses, may be zero.<a name="line.165"></a>
<FONT color="green">166</FONT>             */<a name="line.166"></a>
<FONT color="green">167</FONT>            public int getAddressCount()                { <a name="line.167"></a>
<FONT color="green">168</FONT>                int count = broadcast() - network() + (isInclusiveHostCount() ? 1 : -1);<a name="line.168"></a>
<FONT color="green">169</FONT>                return count &lt; 0 ? 0 : count;<a name="line.169"></a>
<FONT color="green">170</FONT>            }<a name="line.170"></a>
<FONT color="green">171</FONT>    <a name="line.171"></a>
<FONT color="green">172</FONT>            public int asInteger(String address) {<a name="line.172"></a>
<FONT color="green">173</FONT>                return toInteger(address);<a name="line.173"></a>
<FONT color="green">174</FONT>            }<a name="line.174"></a>
<FONT color="green">175</FONT>    <a name="line.175"></a>
<FONT color="green">176</FONT>            public String getCidrSignature() {<a name="line.176"></a>
<FONT color="green">177</FONT>                return toCidrNotation(<a name="line.177"></a>
<FONT color="green">178</FONT>                        format(toArray(address())),<a name="line.178"></a>
<FONT color="green">179</FONT>                        format(toArray(netmask()))<a name="line.179"></a>
<FONT color="green">180</FONT>                );<a name="line.180"></a>
<FONT color="green">181</FONT>            }<a name="line.181"></a>
<FONT color="green">182</FONT>    <a name="line.182"></a>
<FONT color="green">183</FONT>            public String[] getAllAddresses() {<a name="line.183"></a>
<FONT color="green">184</FONT>                int ct = getAddressCount();<a name="line.184"></a>
<FONT color="green">185</FONT>                String[] addresses = new String[ct];<a name="line.185"></a>
<FONT color="green">186</FONT>                if (ct == 0) {<a name="line.186"></a>
<FONT color="green">187</FONT>                    return addresses;<a name="line.187"></a>
<FONT color="green">188</FONT>                }<a name="line.188"></a>
<FONT color="green">189</FONT>                for (int add = low(), j=0; add &lt;= high(); ++add, ++j) {<a name="line.189"></a>
<FONT color="green">190</FONT>                    addresses[j] = format(toArray(add));<a name="line.190"></a>
<FONT color="green">191</FONT>                }<a name="line.191"></a>
<FONT color="green">192</FONT>                return addresses;<a name="line.192"></a>
<FONT color="green">193</FONT>            }<a name="line.193"></a>
<FONT color="green">194</FONT>    <a name="line.194"></a>
<FONT color="green">195</FONT>            /**<a name="line.195"></a>
<FONT color="green">196</FONT>             * {@inheritDoc}<a name="line.196"></a>
<FONT color="green">197</FONT>             * @since 2.2<a name="line.197"></a>
<FONT color="green">198</FONT>             */<a name="line.198"></a>
<FONT color="green">199</FONT>            @Override<a name="line.199"></a>
<FONT color="green">200</FONT>            public String toString() {<a name="line.200"></a>
<FONT color="green">201</FONT>                final StringBuilder buf = new StringBuilder();<a name="line.201"></a>
<FONT color="green">202</FONT>                buf.append("CIDR Signature:\t[").append(getCidrSignature()).append("]")<a name="line.202"></a>
<FONT color="green">203</FONT>                    .append(" Netmask: [").append(getNetmask()).append("]\n")<a name="line.203"></a>
<FONT color="green">204</FONT>                    .append("Network:\t[").append(getNetworkAddress()).append("]\n")<a name="line.204"></a>
<FONT color="green">205</FONT>                    .append("Broadcast:\t[").append(getBroadcastAddress()).append("]\n")<a name="line.205"></a>
<FONT color="green">206</FONT>                     .append("First Address:\t[").append(getLowAddress()).append("]\n")<a name="line.206"></a>
<FONT color="green">207</FONT>                     .append("Last Address:\t[").append(getHighAddress()).append("]\n")<a name="line.207"></a>
<FONT color="green">208</FONT>                     .append("# Addresses:\t[").append(getAddressCount()).append("]\n");<a name="line.208"></a>
<FONT color="green">209</FONT>                return buf.toString();<a name="line.209"></a>
<FONT color="green">210</FONT>            }<a name="line.210"></a>
<FONT color="green">211</FONT>        }<a name="line.211"></a>
<FONT color="green">212</FONT>    <a name="line.212"></a>
<FONT color="green">213</FONT>        /**<a name="line.213"></a>
<FONT color="green">214</FONT>         * Return a {@link SubnetInfo} instance that contains subnet-specific statistics<a name="line.214"></a>
<FONT color="green">215</FONT>         * @return new instance<a name="line.215"></a>
<FONT color="green">216</FONT>         */<a name="line.216"></a>
<FONT color="green">217</FONT>        public final SubnetInfo getInfo() { return new SubnetInfo(); }<a name="line.217"></a>
<FONT color="green">218</FONT>    <a name="line.218"></a>
<FONT color="green">219</FONT>        /*<a name="line.219"></a>
<FONT color="green">220</FONT>         * Initialize the internal fields from the supplied CIDR mask<a name="line.220"></a>
<FONT color="green">221</FONT>         */<a name="line.221"></a>
<FONT color="green">222</FONT>        private void calculate(String mask) {<a name="line.222"></a>
<FONT color="green">223</FONT>            Matcher matcher = cidrPattern.matcher(mask);<a name="line.223"></a>
<FONT color="green">224</FONT>    <a name="line.224"></a>
<FONT color="green">225</FONT>            if (matcher.matches()) {<a name="line.225"></a>
<FONT color="green">226</FONT>                address = matchAddress(matcher);<a name="line.226"></a>
<FONT color="green">227</FONT>    <a name="line.227"></a>
<FONT color="green">228</FONT>                /* Create a binary netmask from the number of bits specification /x */<a name="line.228"></a>
<FONT color="green">229</FONT>                int cidrPart = rangeCheck(Integer.parseInt(matcher.group(5)), 0, NBITS);<a name="line.229"></a>
<FONT color="green">230</FONT>                for (int j = 0; j &lt; cidrPart; ++j) {<a name="line.230"></a>
<FONT color="green">231</FONT>                    netmask |= (1 &lt;&lt; 31-j);<a name="line.231"></a>
<FONT color="green">232</FONT>                }<a name="line.232"></a>
<FONT color="green">233</FONT>    <a name="line.233"></a>
<FONT color="green">234</FONT>                /* Calculate base network address */<a name="line.234"></a>
<FONT color="green">235</FONT>                network = (address &amp; netmask);<a name="line.235"></a>
<FONT color="green">236</FONT>    <a name="line.236"></a>
<FONT color="green">237</FONT>                /* Calculate broadcast address */<a name="line.237"></a>
<FONT color="green">238</FONT>                broadcast = network | ~(netmask);<a name="line.238"></a>
<FONT color="green">239</FONT>            } else {<a name="line.239"></a>
<FONT color="green">240</FONT>                throw new IllegalArgumentException("Could not parse [" + mask + "]");<a name="line.240"></a>
<FONT color="green">241</FONT>            }<a name="line.241"></a>
<FONT color="green">242</FONT>        }<a name="line.242"></a>
<FONT color="green">243</FONT>    <a name="line.243"></a>
<FONT color="green">244</FONT>        /*<a name="line.244"></a>
<FONT color="green">245</FONT>         * Convert a dotted decimal format address to a packed integer format<a name="line.245"></a>
<FONT color="green">246</FONT>         */<a name="line.246"></a>
<FONT color="green">247</FONT>        private int toInteger(String address) {<a name="line.247"></a>
<FONT color="green">248</FONT>            Matcher matcher = addressPattern.matcher(address);<a name="line.248"></a>
<FONT color="green">249</FONT>            if (matcher.matches()) {<a name="line.249"></a>
<FONT color="green">250</FONT>                return matchAddress(matcher);<a name="line.250"></a>
<FONT color="green">251</FONT>            } else {<a name="line.251"></a>
<FONT color="green">252</FONT>                throw new IllegalArgumentException("Could not parse [" + address + "]");<a name="line.252"></a>
<FONT color="green">253</FONT>            }<a name="line.253"></a>
<FONT color="green">254</FONT>        }<a name="line.254"></a>
<FONT color="green">255</FONT>    <a name="line.255"></a>
<FONT color="green">256</FONT>        /*<a name="line.256"></a>
<FONT color="green">257</FONT>         * Convenience method to extract the components of a dotted decimal address and<a name="line.257"></a>
<FONT color="green">258</FONT>         * pack into an integer using a regex match<a name="line.258"></a>
<FONT color="green">259</FONT>         */<a name="line.259"></a>
<FONT color="green">260</FONT>        private int matchAddress(Matcher matcher) {<a name="line.260"></a>
<FONT color="green">261</FONT>            int addr = 0;<a name="line.261"></a>
<FONT color="green">262</FONT>            for (int i = 1; i &lt;= 4; ++i) {<a name="line.262"></a>
<FONT color="green">263</FONT>                int n = (rangeCheck(Integer.parseInt(matcher.group(i)), -1, 255));<a name="line.263"></a>
<FONT color="green">264</FONT>                addr |= ((n &amp; 0xff) &lt;&lt; 8*(4-i));<a name="line.264"></a>
<FONT color="green">265</FONT>            }<a name="line.265"></a>
<FONT color="green">266</FONT>            return addr;<a name="line.266"></a>
<FONT color="green">267</FONT>        }<a name="line.267"></a>
<FONT color="green">268</FONT>    <a name="line.268"></a>
<FONT color="green">269</FONT>        /*<a name="line.269"></a>
<FONT color="green">270</FONT>         * Convert a packed integer address into a 4-element array<a name="line.270"></a>
<FONT color="green">271</FONT>         */<a name="line.271"></a>
<FONT color="green">272</FONT>        private int[] toArray(int val) {<a name="line.272"></a>
<FONT color="green">273</FONT>            int ret[] = new int[4];<a name="line.273"></a>
<FONT color="green">274</FONT>            for (int j = 3; j &gt;= 0; --j) {<a name="line.274"></a>
<FONT color="green">275</FONT>                ret[j] |= ((val &gt;&gt;&gt; 8*(3-j)) &amp; (0xff));<a name="line.275"></a>
<FONT color="green">276</FONT>            }<a name="line.276"></a>
<FONT color="green">277</FONT>            return ret;<a name="line.277"></a>
<FONT color="green">278</FONT>        }<a name="line.278"></a>
<FONT color="green">279</FONT>    <a name="line.279"></a>
<FONT color="green">280</FONT>        /*<a name="line.280"></a>
<FONT color="green">281</FONT>         * Convert a 4-element array into dotted decimal format<a name="line.281"></a>
<FONT color="green">282</FONT>         */<a name="line.282"></a>
<FONT color="green">283</FONT>        private String format(int[] octets) {<a name="line.283"></a>
<FONT color="green">284</FONT>            StringBuilder str = new StringBuilder();<a name="line.284"></a>
<FONT color="green">285</FONT>            for (int i =0; i &lt; octets.length; ++i){<a name="line.285"></a>
<FONT color="green">286</FONT>                str.append(octets[i]);<a name="line.286"></a>
<FONT color="green">287</FONT>                if (i != octets.length - 1) {<a name="line.287"></a>
<FONT color="green">288</FONT>                    str.append(".");<a name="line.288"></a>
<FONT color="green">289</FONT>                }<a name="line.289"></a>
<FONT color="green">290</FONT>            }<a name="line.290"></a>
<FONT color="green">291</FONT>            return str.toString();<a name="line.291"></a>
<FONT color="green">292</FONT>        }<a name="line.292"></a>
<FONT color="green">293</FONT>    <a name="line.293"></a>
<FONT color="green">294</FONT>        /*<a name="line.294"></a>
<FONT color="green">295</FONT>         * Convenience function to check integer boundaries.<a name="line.295"></a>
<FONT color="green">296</FONT>         * Checks if a value x is in the range (begin,end].<a name="line.296"></a>
<FONT color="green">297</FONT>         * Returns x if it is in range, throws an exception otherwise.<a name="line.297"></a>
<FONT color="green">298</FONT>         */<a name="line.298"></a>
<FONT color="green">299</FONT>        private int rangeCheck(int value, int begin, int end) {<a name="line.299"></a>
<FONT color="green">300</FONT>            if (value &gt; begin &amp;&amp; value &lt;= end) { // (begin,end]<a name="line.300"></a>
<FONT color="green">301</FONT>                return value;<a name="line.301"></a>
<FONT color="green">302</FONT>            }<a name="line.302"></a>
<FONT color="green">303</FONT>    <a name="line.303"></a>
<FONT color="green">304</FONT>            throw new IllegalArgumentException("Value [" + value + "] not in range ("+begin+","+end+"]");<a name="line.304"></a>
<FONT color="green">305</FONT>        }<a name="line.305"></a>
<FONT color="green">306</FONT>    <a name="line.306"></a>
<FONT color="green">307</FONT>        /*<a name="line.307"></a>
<FONT color="green">308</FONT>         * Count the number of 1-bits in a 32-bit integer using a divide-and-conquer strategy<a name="line.308"></a>
<FONT color="green">309</FONT>         * see Hacker's Delight section 5.1<a name="line.309"></a>
<FONT color="green">310</FONT>         */<a name="line.310"></a>
<FONT color="green">311</FONT>        int pop(int x) {<a name="line.311"></a>
<FONT color="green">312</FONT>            x = x - ((x &gt;&gt;&gt; 1) &amp; 0x55555555);<a name="line.312"></a>
<FONT color="green">313</FONT>            x = (x &amp; 0x33333333) + ((x &gt;&gt;&gt; 2) &amp; 0x33333333);<a name="line.313"></a>
<FONT color="green">314</FONT>            x = (x + (x &gt;&gt;&gt; 4)) &amp; 0x0F0F0F0F;<a name="line.314"></a>
<FONT color="green">315</FONT>            x = x + (x &gt;&gt;&gt; 8);<a name="line.315"></a>
<FONT color="green">316</FONT>            x = x + (x &gt;&gt;&gt; 16);<a name="line.316"></a>
<FONT color="green">317</FONT>            return x &amp; 0x0000003F;<a name="line.317"></a>
<FONT color="green">318</FONT>        }<a name="line.318"></a>
<FONT color="green">319</FONT>    <a name="line.319"></a>
<FONT color="green">320</FONT>        /* Convert two dotted decimal addresses to a single xxx.xxx.xxx.xxx/yy format<a name="line.320"></a>
<FONT color="green">321</FONT>         * by counting the 1-bit population in the mask address. (It may be better to count<a name="line.321"></a>
<FONT color="green">322</FONT>         * NBITS-#trailing zeroes for this case)<a name="line.322"></a>
<FONT color="green">323</FONT>         */<a name="line.323"></a>
<FONT color="green">324</FONT>        private String toCidrNotation(String addr, String mask) {<a name="line.324"></a>
<FONT color="green">325</FONT>            return addr + "/" + pop(toInteger(mask));<a name="line.325"></a>
<FONT color="green">326</FONT>        }<a name="line.326"></a>
<FONT color="green">327</FONT>    }<a name="line.327"></a>




























































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